Actinokentia Dammer, Bot. Jahrb. Syst. 39: 20 (1906)Protologue

Primary tabs

http://media.e-taxonomy.eu/palmae/photos/palm_tc_2738_1.jpg

Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)

Two species in New Caledonia, occurring in wet forests on serpentine soils from 60–1000 m in the southern part of the island. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)

Discussion

Diagnosis

Biology And Ecology

Etymology

Uses

Description

  • Solitary, small to moderate, unarmed, pleonanthic, monoecious palms. Stem slender, erect, prominently ringed with somewhat sunken leaf scars, sometimes with prickly roots. Leaves pinnate; sheaths thick, forming a crownshaft; petiole short, rounded abaxially, channelled adaxially, or elongate and terete; leaflets regularly arranged, lanceolate, acute to tapering, single-fold, adaxially waxy or glabrous, abaxially waxy tomentose with large ramenta along the midribs, midribs conspicuous, second largest ribs those along margins, transverse veinlets not evident. Inflorescences infrafoliar, protandrous, divaricately branched to 3 orders basally, 1–2 orders distally; peduncle short; prophyll tubular, pointed, rather thin, indistinctly 2-keeled, completely encircling the peduncle at insertion and enclosing the peduncular bract, caducous; peduncular bract like the prophyll but lacking keels; rachis longer than the peduncle bearing spirally arranged, spreading, acute bracts subtending branches and rachillae; rachilla bracts prominent, rounded, lip-like and shorter than the flowers or acute and exceeding the flowers, subtending triads basally, paired or solitary staminate flowers distally, in broadened depressions in the rachillae; bracteoles surrounding the pistillate flower sepal-like, outermost bracteole prominent, ca. 1/2 as long or as long as the inner bracteoles. Staminate flowers symmetrical, larger at anthesis than the pistillate buds; sepals 3, distinct, broadly imbricate and rounded, scarcely longer than broad, the outer often prominently keeled or pouch-like near the apex; petals 3, distinct, valvate, boat-shaped; stamens 19–50, filaments erect or nearly so at the apex in bud, anthers erect in bud, linear, dorsifixed, slightly emarginate apically, bifid basally, latrorse, the connective elongate; pistillode as long as the stamens in bud, tapered to a slender apex from a broad base. Pollen ellipsoidal or asymmetric to pyriform; aperture a distal sulcus; ectexine tectate, perforate, aperture margin similar or slightly finer; infratectum columellate; longest axis 48–60 µm [1/2]. Pistillate flowers, buds usually well developed at staminate anthesis, symmetrical; sepals 3, distinct, broadly imbricate and rounded; petals 3, distinct, imbricate except for briefly valvate apices; staminodes 3, small, tooth-like, borne at one side of the gynoecium; gynoecium unilocular, uniovulate, stigmas 3, prominent, recurved, ovule pendulous, hemianatropous. Fruit ellipsoidal with apical stigmatic remains; epicarp smooth, mesocarp underlain by a shell of short, pale sclereids, elliptic in outline at surface, the sclereid shell over parenchyma with flat, anastomosing longitudinal fibres adherent to the endocarp, tannin cells lacking, or few and interspersed among the fibres, endocarp thin, fragile, not operculate. Seed attached by an elongate hilum, raphe branches anastomosing, endosperm homogeneous; embryo basal. Germination adjacent-ligular; eophyll bifid. Cytology not known. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)

Relationships

Bibliography

A. J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008
B. World Checklist of Arecaceae